Over the last couple of weeks I’ve been subjected to my mind playing tricks on me, leading me to long sessions of rather deep thinking about the texture of the universe around me. The latest of these happened yesterday on the train ride home. We had spent the day talking about sensory experiences, and surely enough, the first thing that happened when I looked out the window of the train, I was hit by the thought: I know light travels, but just HOW does it travel? I honestly couldn’t grasp the idea of light traveling anymore. I have always just accepted it for being what it is. After all, it’s pretty well documented, and I don’t doubt that light travels. It was HOW does it travel? HOW do I sense the trees outside the window? I don’t just think light as in light from the direct source (the Sun, a lamp), but more in the reflected sense. Light that has come from the Sun, hit the nature and is now directed towards my eyes.
The first problem was that if light just traveled through space, wouldn’t the trees seem like they were coming closer? You need to understand, I had connected the idea of light with the idea of picture. If light traveled, it seemed logical that the trees would have a movie-3D effect, coming “out of the picture” so to say. Try and see if you can follow my thought on this. Look around the room you’re in (or if you’re fortunate enough to be outside, see if you can find a tree). Look at a thing with the thought in mind: light travels, and it travels towards you. Doesn’t it seem natural that, if light has these characteristics, everything will seem like it’s traveling towards you? And when things travel towards you, wouldn’t they get larger? Wouldn’t a small object far away turn into a large object when it “hit” your eyes?
Though completely indulged in this thought, I had enough sense to try to think of some better explanation of light traveling, and the way we perceive this, because it just isn’t so that things move towards us, at least not visually. To overcome this problem, I drew the conclusion that the reason we aren’t bombarded by trees coming towards us, is because what we see is “the complete picture”. Not just single objects in our visual field, but our entire visual field comes towards us all the time. We’re constantly bombarded with light (when there is light, of course), and if we’re constantly bombarded with the complete picture, one thing wouldn’t have that unreal movie-3D effect compared to the others. But in my mind, it still created the issue that now EVERYTHING would just arrive at my eyes in this 3D-style. I still had the idea of the light “evolving” through its travel. I expected all of the light in my visual field to hit me at the same time (understood as in: it had taken an equal amount of time for the light to hit my eyes no matter if it came from a tree 2 meters away or a forest 500 meters away). This is of course a very faulty idea of how light travels, if it is to make any sense. Though (probably) still not creating a movie-3D effect, as it did in my mind, it seems light acting that way would make the world two-dimensional instead of our beloved three-dimensional perception.
As I came to my third idea of how light travels, I was starting to verge on the outskirts of the dimensional thinking just described. I understood that the complete visual field-picture theory wouldn’t quite make it. At least not in the form presented. I had a serious problem understanding how trees could appear smaller when they were in the distance, compared to trees immediately in front of me. I was still slightly messed up from the thought about all the light hitting me at the same time (and had been for about 30 strange minutes by this time). I convinced myself that the reason for the smaller trees was that the light had traveled a greater distance to get from them to me, than the light from the trees near-by, and thus the light was weaker – and couldn’t muster the energy to “grow”. Which of course, with that conclusion, is utter nonsense.
However, it was the best conclusion I could draw before my train ride had come to an end and I suddenly realized 40 minutes had gone by, and my mind had been unreasonably messed up by somewhat subconscious thoughts. It’s not until now, writing it down, I feel like I can understand the concept of light’s travel. I’m inclined to believe that the reason for the trees to seem smaller at a distance is the idea that light of course travels at its given speed, and thus will hit me at different times (a tree right in front of me will hit me before a tree 500 meters hits me), and since light is constantly sent out, I will receive new pictures ALL the time, and the perspective will always be intact because, even though I receive pictures from ALL the objects ALL the time, I will receive newer/younger pictures from the things close to me, and they will therefore be shown as close to real-size as can be, whereas the pictures traveling a vast distance will have aged, and.. well this sounds like the “growth”-theory again. It went wrong somewhere in there.
Okay, it’s time I revive me relationship with physics.